The low-temperature properties of EuMg\(_2\) Bi\(_2\)  have been studied in detail [1]}, [2]}, [3]}. The magnetic structure below \(T_{\rm N} = 6.7(1)\)  K is an A-type AFM structure, in which the Eu moments with spin \(S=7/2\)  and spectroscopic splitting factor \(g=2\)  are ferromagnetically aligned parallel to an Eu layer of the structure, whereas the moments in adjacent layers along the \(c\)  axis are aligned antiparallel. The specific heat \(C_{\rm p}\)  exhibits a \(\lambda \) -type anomaly at \(T_{\rm N}\)  and short-range magnetic order at temperatures \(T\)  above \(T_{\rm N}\) . The magnetic entropy \(\approx R\ln (8)\)  at \(T\gg T_{\rm N}\)  is consistent with that expected for Eu\(^{2+}\)  magnetic moments with magnitude \(\mu =gS\,\mu _{\rm B} = 7\,\mu _{\rm B}\)  with \(g=2\)  and spin \(S= 7/2\) , where \(\mu _{\rm B}\)  is the Bohr magneton. The \(ab\) -plane electrical resistivity \(\rho _{ab}(T)\)  exhibits metallic character with a mild and disorder-sensitive upturn below \(\sim 23\)  K.
